Telegraphic sending key



Feb. 21, 1928. 1,660,173

N. WQM LACHLAN TELEGRAPHIC SENDING KEY Filed April 19, 1923 NORMAN W.McLACHLAN gmvemtoz 7 wheel.

the automatic sender'and may conveniently.

Patented Feb. 21, 1928.

UNITED. STATES.

PATENT OFFICE.

NORMAN WILLIAM MoLACI-ILAN, OF CHELM SFOIRD, ENGLAND, ASSIGNOB TO RADIOCORPORATION OF AMERICA, A CORPORATION OF DELAWARE.

TELEGRAPHIO snNnInG KEY.

Application filed April 19, 1923, Serial No. 633,045, and in GreatBritain April 20, 1922.

This invention relates to the sending keys used in telegraphy and itsobject isto provide a key in which a'small movement due to an automaticsender, such as a Wheatstone transmitter, shall produce a large movementof a contact arm.

According to this invention I make fastwith a fly wheel, which can berapidly rotated, one member of a clutch, the other member of which canbe moved into and out of engagement with the first member by anautomatic sender, and I mount on this second member a contact arm sothat a small movement of translationof the second member causes it toengage the first member and therefore to be carried round rapidly andwith considerable force by the fly wheel, while on its being disengagedit is brought back to its normal position by a spring. Preferably thefirst member consists of a female cone formed in or on the fly wheel,and the second member consists of a male cone mounted so that it is freeto rotate but cannot move longitudinally upon a' rod which passesthrough an axial hole in the fly This rod is moved longitudinally by beconnected to a band carrying a shoe in contact with a continuouslyrota-ting drum provided with a coil through which a current is sentaccording to the signals to .be transmitted. Y I

Insome cases I may provide in the female cone a coil, current in whichis controlled by the automatic sender, to cause magnetic attractionbetween the two parts of the clutch, or there may be a coil in bothmembers of the clutch, and aconstant. current can flow through one coilwhile a current reversed by the automatic sender may flow through theother.

My invention is illustrated by the accompanying drawing, in which Figure1 is a longitudinal sectionof a con tact arm and the operating mechanismtherefor,

Figure 2 is an end view of the apparatus shown in Figurel,

Figure 3 1s a sectional vlew of a modified form of the apparatus shownin Figure 1,

And Figure 4 is an end view of the apparatus shown in Figure 3.

In Fig. 1, A is a fly wheel fast with a belt pulley B by which it'can berotated at a high constant speed. In the fly wheel is formed a femalecone G into which fits a male cone D mounted so that it can rotatebetween collars E on a rod F connected at one end through a spring G toa fixed sup port H and at the other to'a band I suclias is described inmy British specification No. 176,932 March 22, 1922. This band passesround a constantly rotating drum J and carries shoes K which bear uponthe surface of the drum, while the end of the band is connected througha spring L to a fixed support When a current passes through the coil inthe drum J the shoes are momentarily attracted to the drum andthe'refore'the rod F is moved to the right, bringing the cone D intoengagement with the cone C, so that the cone D is turned by the rotationof the fly wheelA; i

The cone D has fast upon it acontact arm N which, as shownin Figure 2,is adapted to make contact with a fixed contact 0.

P is a spring which restores the arm to its normal position as soon asthe rod F is, on the cessation of the current through the coil in thedrum J, moved to the left by the spring G, thus freeing cone D from coneC.

Q, R, are coils arranged in the cones C, D, respectively, through one ofwhich a constant current can flow, other can flow a current controlledby the automatic sender, so that when the cones-engage one another theirfrictional engagement may be increased by magnetic attraction.

Figs. 3 and 4 show a modified form of clutch in which the interiorsurface of the fly wheel is provided with a coned groove into which fitconed segments S, S, pivoted to the ends of arms, T, T, pivoted to asleeve on the rod F. When the rod is moved to the right the arms T causethe segments S to engage in the groove in the'fly wheel and thereforethe segments are carried round with the fly wheel until an arm N fast onone of them comes as before against a fixed contact.

Having described my invention,.what I claim is: r

1. In a telegraphic sending key, the combination of a fly wheel, aclutch, one member of which is fast with the fly wheel, and

while through the 7 ment of the two members of the clutch by magneticattraction.

3. In radio transmitting apparatus,a key comprising a fixed contactmember, a movable contact member cooperating therewith and mounted forrotation, a rotating member for driving said movable contact mem ber byfrictional engagement and rotatable means for effecting engagementbetween said movable contact member and said driving member inaccordance with keying. 7

4. In radio transmitting apparatus, a key comprising a fixed contactmember, a movable contact member arranged for rotation, a rotatabledriving member for rotating said contact member in one direction byfrictional engagement therewith, means for rotating said movable contactmember in the other direction and rotatable means for causing frictionalengagement between said movable contact member and said driving memberin accordance with keying;

5. In radio transmitting apparatus, a key comprising a'fixed contactmember, a movable contact member rotatable into and out of contacttherewith, means for normally maintaining said membersout of contact, arotatable driving member for rotating said movable contact member byfrictional engagement therewith to engage said contact members androtatable means for causing frictional engagement between said drivingmember and said movable contact member in accordance with keying.

6. In radio transmitting apparatus, a key comprising a fixed contactmember, a movable contact member rotatable into and out of contacttherewith, means for normally maintaining said members out of contact, arotatable driving member for rotating said ..movable contact member byfrictional engagement therewith to engage said Contact members and meansfor causing frictional engagement between said driving member and saidmovable contact member in accordance with keying, said last mentionedmeans compris ng means for effecting axial.

motion between said movable contact member and said driving member foreifectlng frictional engagement of the former by the latter.

7. In radio transmitting apparatus, a key 8. In a radio transmittingapparatus, a

key comprising a fixed contact member, a

movable contact member cooperating there" with and mounted for rotation,a clutch for intermittently rotating said movable contact member, meansfor normally maintaining sa1d clutch in the disengaged positlon, and acontinuously rotating drum cooperating with said clutch to impartmovement'to the aforesaid movable contact member in accordance withsignal impulses impressed on the drum.

9. In a, radio transmitting apparatus, a key comprising a fixed contactmember, a

movable contact member cooperating therewith, a clutch comprisingrelatively movable members one of said last mentioned members beingassociated with said movable contact member, means normally-to maintainsaid clutch members in spaced relation and continuously rotatable meansassociated in frictional relation with one of said clutch members togive the said member axial move-.

ment, whereby it may be brought into engagement with the other clutchmember to rotate the movable contact member.

10. In a radio transmitting apparatus, a fixed contact, a pair ofcomplementary clutch members, means for rotating one of said clutchmembers, a contact member on the' other clutch member, and means forengag- 111g and disengaging sa1d clutch member in accordance withkeying. V V

11. In a radio transmitting apparatus, a fixed contact, a pair ofcomplementary clutch members, means for rotating one of said clutchmembers, a contact member on the other clutch member, and frictionalmeans including a continuously rotating drum for engaging anddisengaging said bers.

NORMAN WILLIAM MQLACHLAN;

clutch mem-I

